Wheel construction are known in which a hub is constructed of a rigid moldable synthetic resin, and which has bonded around the outer peripheral surface thereof an annular tread made from a relatively softer moldable synthetic resin. An example of such construction is disclosed in my U.S. Pat. No. 3,894,776. The wheel construction illustrated in my aforementioned patent has proven to be quite satisfactory but for a limited market. Customers purchasing wheels desire the wheel to have a particular appearance characteristic to blend with the structure on which the wheel is to be mounted. Some customers desire the wheel to take on the appearance of a sturdy steel wheel and yet other customers desire the wheel to have the appearance of a hard rubber wheel. Steel appearing wheels are good in some areas of use but where corrosive agents are utilized in the adjacent environment, steel will rust and become unsightly. Thus, and in order to enhance the salability of wheel constructions and still meet the customer's demands, it is highly desirable to provide a structure which will permit the assembly of wheel constructions having the desired aesthetic value to the customer without having to resort to different methods of construction for these wheels.
Accordingly, the objects and purposes of this invention include:
1. The provision of a wheel construction having the known advantages and performance characteristics resulting from a tread made of a moldable synthetic resin being injection molded onto a hub of a rigid synthetic resin, but not limited in appearance to one particular type of material.
2. The provision of a wheel construction, as aforesaid, which will permit me to utilize the same bearing construction that I have used in some of my earlier developments shown in U.S. Pat. Nos. 3,807,817 and 4,072,373.
3. To provide a wheel construction, as aforesaid, which is particularly adaptable for use in the wheels of a caster or the like wherein the treatment received by the bearing assembly, even under normal conditions of use, is severe by any reasonable standard.
4. To provide a wheel construction, as aforesaid, which has a sufficient structural simplicity that it can be assembled rapidly, accurately and inexpensively.
5. To provide a wheel construction, as aforesaid, comprised of a minimum number of parts, each part being of such structural configuration that it is capable of being assembled so that the strength of the assembly is increased during the assembly.